Optical brighteners of the stilbene series



2 5 2 9 9 CROSS REFEiEiiCE EYAMlNER United States Patent ICC 3,394,173

Patented July 23, 1968 3,394,173 brightening agent, to be fully satisfactory, also draw sutfi' O ICAL BRIGHTENERS OF THE ciently from a laundering bath containing the same onto STILBENE SERIES cellulosic and the like textile materials, preferably Heinrich Hausermann, Riehen, Switzerland, assignor to with the chlorine-yielding bleaching agent present in the J. R. Geigy A.G., Basel, Switzerland bath.

N 0 Drawing. F|led De c. l8, 1 964, Ser. No. 419,566 Known brightening agents which possess satisfactory Claims prlonty, appllctitgoylgygg 1963 chlorine-fastness, and would also impart neutral white shades to the treated cellulosic materials, fail because their 8 Claims (CL 260-507) afiinity to cellulose fibers is so low that they do not draw 10 sufficiently onto these fibers from -a bath containing es- ABSTRACT OF THE DISCLOSURE sentially non-ionogenic detergent agent under normal Optical brightening agents are provided which in the laundering and bleaching conditions. free acid form are of the formula: The present invention remedies these drawbacks of SIO3X SOQX R-COHN CO-HN CH=CH- NHC 0- NH co-R I L l.n L J I wherein R R and X are as defined in the specification. the known brighteners by providing brightening agents Such agents are useful in the optical brightening of orwhich, in the free acid form, are of the formula S 0=X SOsX R|CO HN-CO HNCH=CH-NH CO -NH I 00-11: L ]m L ln soiH SOsH (I) ganic textile fibers containing hydroxyl groups, especially in which formulae genuloslc. g b T mvemlon Provides organic. R and R each represent an unsubstituted or non-chromoi opuca 1y ng.tened. by uuhzmg the new opncal genically substituted hydrocarbon radical as defined righteners of the invention. below,

X represents alkyl of from 1 to 5 carbon atoms, and preferably methyl or ethyl; lower alkoxy-lower alkyl, The present invention concerns new optical brighteners e.g. fi-methoxyor ethoxy-ethyl or 'y-methoxy-propyl;

of the stilbene series, processes for the production thereof, alkyl or from 1 to 2 carbon atoms substituted by detergents and brightening liquors containing these brightphenyl, chlorophenyl, bromophenyl, lower alkylphenyl eners as active ingredients, a method for the optical or lower alkoxyphenyl; or di-lower alkyl-amino, pyrbrightening of organic textile fibers containing hydroxyl rolidino, piperidino, morpholino, lower alkyl-morphogroups, especially cellulosic fibers, with the aid of the lino, and hexamethylene imino,

new brighteners, as well as industrial products, the m and n represent 0 0 aforesaid organic fibers optically brightened by a 9" which brighteners, for the first time, combine:

tent of the new optical brighteners of the stilbene series. (a) Satisfactory resistance to chlorine, so that they It is known that opncal bnghteners of the class of can be used in detergents and laundering liquors together N-substituted 4,4'-diaminostilbene-2,2-disulphonic acids with chlorineqidding bleaching agents have only slight fastness to chlorine so that they can be (b) A neutral white shade imparted to the treated used with compounds giving off chlorine in washing agents tile cellulosic materials and and liquors only at considerable expense to the optical (0) Good amnity to cellulosic fibers when drawing thereon from liquors containing non-ionogenic compounds It 18 however, increasingly desired by industry to have as the essential detergent constituents avaflalzle deiergenis t i hqtuors "i' f i h By non-chromogenic substitutents are meant substit- Same a smg e men F' enngrfi uent groups which do not impart color to the brightener cal bleaching and brightening white textile materials. At molecule the same time, it 1s requ1red that the brightening agents Each of R1 and R2 represent different or preferably impart a neutral whlte shade Wnh a blmsh or possbly identical radicals selected from the group consisting of very light violet hue, which appears very faintly pinkish O to the naked eye, but not a greenish hue, to the brightened 6 d y textile materials. (lowflr 305 Known brightening agents which possess satisfactory a'U fastness to chlorine and could therefore be used in detera'( Y)' gems and the like media, containing chlofine'yielding wherein the alkoxy moiety has from 2 to 4 carbon atoms, compounds, have an undesirable tendency to impart an increasingly greenish shade to the treated materials, es- (Rm pecially after repeated washing with liquors containing (3H,)- such known brighteners.

Moreover, since preferred liquid detergents and launder- G ing baths nowadays contain non-ionogenic rather than ionogenic detergent constituents, it is necessary that a and wherein Lower used in connection with alkyl" and the like aliphatic radicals means that these radicals have from 1 to 4 carbon atoms.

Optimal brightening effects in the above described combination of properties are obtained with brightening agents of the formula SOzX wherein each R represents lower alkoxy, hydroxy-lower alkoxy or lower alkoxy-lower alkoxy, and is linked to the respective benzene nucleus ortho or para to the adjacent OC-group, both R in the above formula being preferably identical, and

each of R and R represents hydrogen, lower alkyl, lower alkoxy, hydroxy-lower alkoxy or lower alkoxy-lower alkoxy, and

X is as previously defined herein.

In aqueous solutions of adetergent containing brighteners according to the invention which are used for the brightening of the fiber mentioned, the content of brightener is preferably 0.005 to 0.5% by weight calculated on the weight of the detergent mixture. Suitable detergents contain as wash-active substances, e.g. anionic compounds, e.g. alkali metal salts, particularly sodium salts of higher fatty acids, alkali metal alkyl-aryl-sulfonates, especially dodecylbenzene sulfonate or tetrapropylbenzene sulfonate,

8101 802K K H: -CH3 NO 0 R0? NMSO: N0 oxidation HOIS l l SOaH alkali metal secondary alkyl sulfates having at least one higher molecular secondary alkyl radical, fatty alcohol sulfates such as dodecyl sulfate or sulfated fatty alcohol polyglycol ethers such as sulfated addition products of 2 to 3 mols of ethylene oxide to dodecyl alcohol. The new brighteners draw easily and evenly onto cellulose material even in the presence of non-ionogenic wash-active substances, e.g. of polyglycol ethers containing lipophilic radicals. Examples of such non-ionogenic was-active compounds are fatty alcohol polyglycol ethers or alkylphenol polyglycol ethers. In addition, the detergents can contain the additives usual in the textile finishing industry such as water-soluble phosphates, silicates, carbonates, sulfates such as sodium sulfate water softeners, foam stabilizers and/ or textile softeners.

Because of their excellent fastness to chlorine, the stilbene compounds according to the invention can be used without undue loss of brightening effect in detergents containing chlorine-yielding bleaching agents.

Such bleaching agents are, for instance, open or cyclic compounds containing the group N-Cl such as N.N- dichloroisocyanuric acid, chlorohydantoins or N-chloroaryl sulfonic acid amides such as N-chloro-p-toluene sul- SOgH fonic acid amide or N-chloroalkyl sulfonic acid amides as well as such alkali metal or alkaline earth metal hypochlorites which are stable in solid state, e.g. lithium or calcium hypochlorite, these agents can be contained in the detergents and washing liquors, whereas hypochlorites which are instable in a solid state such as sodium or potassium hypochlorite can be used in the washing liquors.

The brightening agents according to the invention draw well from an aqueous solution of the type described above onto organic fibers containing hydroxyl groups, such as cellulose, particularly cotton, and lend to this material a pleasing pure white, bluish fluorescent appearance. Advantageously the brightened fibers have a content of 0.001 to 0.5% of brightening agent, calculated on the weight of the fibers.

Brighteners according to the invention are produced by a process which is illustrated by the diagram below.

The new brightening agent of Formula I are advantageously isolated from the reaction mixture in the form of their alkali metal salts.

SOaH

l reduction acyla tion with No, @-Coc1 a i reduction (VII) SOgX SOQH

l aylation with R,COCl

or with mixture of R COCl+ RzCOCl SO X SOJH SOsH (T R1) aviation with RIC 0 Cl or with mixture of R 0 001+ Etc 0 Cl HOaS The 4,4 diamino-6,6'-(di-alkyl-sulfonyl)-stilbene-3,3'- disulfonic acids of Formula V are obtained by reducing 2-methyl-4-chlorobenzene-1-sulfonic acid chloride with sodium sulfite to form 2-methyl-4-chlorobenzene-l-sulfinic acid, reacting the latter by alkylation or the like, e.g. with dialkyl sulfate to form the corresponding l-alkyl-sulfonyl)-2-methyl-4-chloro benzene; nitrating this substance with a mixture of nitric acid/sulfuric acid to form l-alkylsulfonyl-2-methyl-4-chloro-5-nitrobenzene (Formula II) and reacting this intermediate with aqueous sodium sulfite to form a 2 nitro-4-alkyl-sulfonyl-S-methylbenzene-l-sulfonic acid of Formula III; oxidizing the sodium salt thereof with aqueous sodium hypochlorite to form the corresponding 4,4' dinitro 6,6'-di-alkyl-sulfonyl-stilbene- 3,3-disulfonic acid and reducing the nitro groups to amino groups.

While starting materials of Formula II in which X represents alkyl, are obtained from 1 alkylsulfonyl 2- methyl-4-chloro-benzene by nitration as mentioned above, starting materials in which X represents lower alkoxyalkyl are obtained in an analogous manner, alkoxy-alkylating the above mentioned sulfinic acid in lieu of alkylating the same.

Starting materials of Formula II in which X represents a dialkylamino radical are obtained from 2-methyl-4- chloro-benzene-l-sulfonic acid by nitration to Z-methyl- 4-chloro-5-nitro-benzene-l-sulfonic acid, chlorination with chlorosulfonic acid to 1-chlorosulfonyl-2-methyl-4-chloro- S-nitro-benzene, and reaction of the latter with dialkylamine.

Starting materials in which X represents an unsubstituted or substituted benzyl or phenylethyl radical are obtained by reducing the above mentioned l-chlorosulfonyl-2-methyl-4-chloro-5-nitro-benzene with sodium sul- (or R2) (m, n=1) fite to the corresponding sulfinic acid and simultaneously or successively exchanging the chlorine atom in 4-position by the --SO H group, consuming a second mol of sodium sulfite, and reacting this intermediate with an unsubstituted or substituted benzylor phenyletbylchloride.

By using for acylation of the intermediate of Formula V mixtures of compounds of the formulas R COCl and R COCl there are obtained final mixed brightener products with different substituents R and R in ratios which depend largely on the ratio in which the aforesaid chlorides have been added. These mixtures are used as brightening agents without separation of the individual compounds therefrom, since such separation into individual components would be without any commercial interest.

Intermediate materials of Formula VI in which m and/or n=l are obtained from the intermediate 4,4-diaminostilbene-3,3'-disulfonic acids VII by reaction with p-nitrobenzene carboxylic acid halides and reduction of the nitro groups to amino groups.

Reactive derivatives of organic carboxylic acids of the formula mainly anhydrides, chloride or bromides of these acids, (sometimes also ketenes), and also organic half esters of carbonic acid of the formula in the latter case mainly the chloroformic or bromoformic acid esters of lower alkanols, are used as acylating agents.

In the acylation steps of the above diagram, chlorides and bromides of aromatic carboxylic acids, in particular benzoic acid chlorides or-bromides the ring of which is substituted by lower alkoxy groups and/or lower alkyl groups particularly in one of the orthoand/or the paraposition, are preferred. Examples of such aromatic carboxylic acid chlorides and bromides are 4-methoxyor 4-ethoxy-benzoyl chloride or bromide, 3-methyl-4-methoxy or 2,4-dimethoxy-benzoyl chloride or bromide, Z-methoxy- 4-methylor 2-eth0xy-4-methylbenzoyl chloride or bromide, 2-methoxy-4-ethylor 2-ethoxy-4-ethy1- benzoyl chloride or bromide, 2-methoxy-4,5-dimethylor 2-ethoxy- 4,5'dimethylbenzoyl chloride or bromide, or 3,4,5-trimethoxy-benzoyl chloride or bromide.

The diaminostilbene compounds of Formula V or VII are advantageously acylated in the presence of tertiary organic nitrogen bases, optionally in the presence of inert organic solvents and, preferably, in the absence of water, at a temperature of about 20-120 C., in particular between 80 and 100 C. Suitable tertiary nitrogen bases are, mainly, pyridine and its homologues, trilower alkylamines, triethylenediamine and di-lower alkyl anilines; examples of inert organic solvents are optionally halogenated or nitrated aromatic hydrocarbons.

The following examples illustrate the invention. Where not otherwise stated, parts and percentages are given by weight. The temperatures are in degrees centigrade. The relationship of parts by weight to parts by volume is as that of kilograms to liters. Where not otherwise stated, solutions are aqueous.

S O1CHJ SOiCHa used in the above example is obtained in the following manner:

120 parts of sodium sulfite are dissolved in 480 parts of water. To this solution there are added at a temperature of 65 to 70 within 20 minutes, while stirring well, 142 parts of 2-methyl-4-chlorobenzene-l-sulfonic acid chloride and a solution of 47 parts of sodium hydroxide in 110 parts of water. The addition of the sodium hydroxide solution has to be performed at such a rate, that the pH value of the mixture remains at 8 to 9.

After an additional stirring for minutes at the same temperature and pH, the reaction solution is clarified and the sodium salt of the 2 methyl-4-chlorobenzene-lsulfinic acid is salted out with 15% of solid sodium chloride (calculated on the total weight of the reaction mixture). 106 parts of the sodium salt of the aforesaid sulfinic acid precipitate upon cooling in the form of white, easily water-soluble crystals which are separated by filtration. The free sulfinic acid is obtained from a concentrated aqueous solution of the sodium salt by addition of an excess of hydrochloric acid, and has a melting point of 91.

106 parts of the sodium salt of the above mentioned sulfinic acid are dispersed in 130 parts of water and heated up to 7075. At this temperature, 160 parts of dimethyl sulfate are added within minutes while the pH value of the mixture is adjusted to 8 to 8.5 by simultaneous addition of a sufi'icient amount of aqueous sodium hydroxide solution. After the addition of dimethyl sulfate,

SOBNB SOJNB 40 parts of 4,4-diamino-6,6-dimethylsulfonyl-stilbene- 3,3'-disulfonic acid [intermediate (a)] are suspended in 400 parts by volume of anhydrous pyridine and a solution of 40 parts of 2-ethoxy-4-methylbenzoyl chloride in parts of anhydrous toluene is added while stirring. The mixture obtained is then refluxed for 2 hours at 100-110". At the end of this time, another solution of 40 parts of 2-ethoxy-4-methylbenzoyl chloride in 50 parts of anhydrous toluene is added dropwise and the mixture is heated for another 2 hours at 100-110".

By the end of this time, no more free aromatic amino groups can be traced. The dark colored reaction solution is then allowed to cool.

The reaction product separates out as a yellowish mass which becomes solid when cold. The crude product is purified by first washing with benzene, drying for a short time, suspending it in 1200 parts by volume of 5% sodium carbonate solution, heating the suspension at 7080 while stirring, again cooling, filtering off the yellowish product of the above formula, washing with 2.5 sodium chloride solution and drying at 80 in vacuo. In this way, a pale yellow water-soluble powder is obtained the diluted aqueous solution of which has a blue fluorescence in daylight. If uncolored cellulose fibers are treated with aqueous solutions of the product, then a beatuiful, neutral white effect is obtained on the strata mentioned. The product has remarkable stability to agents giving off chlorine which enables both optical and chemical bleaching to be performed in one bath. Another advantage of the product is that it has the property to draw onto cellulose fibers also in the presence of non-ionogenic washing agents.

The 4,4-diamino 6,6 dimethylsulfonyl-stilbene-3,3'- disulfonic acid of the formula SIO1CH3 SIO2CHa HzN OH=CH NH:

the reaction mixture is stirred at the same temperature and pH for an additional hour. After cooling to 10, the reaction product is filtered off with suction and washed with water. 2-methyl-4-chlorobenzene-l-methyl sulfone, which is thus obtained in a yield of about forms colorless crystals and melts at 70.

51.1 parts of Z-methyl-4-chlorobenzene-1-methyl sulfone are dissolved at 25 in 250 parts of concentrated sulfuric acid. To this solution there are added dropwise at a temperature of 1 to 10 within 1 to 2 hours, while stirring well, a mixture consisting of 17 parts of nitric acid (100% HNO and 17 parts of concentrated sulfuric acid. The whole batch is then stirred at 0 to 10 for a further 3 hours. In order to isolate the formed nitro compound, the reaction mixture is poured on to 600 parts of crushed ice, the nearly white precipitate is filered off and washed well with water. The product is dried at 75 under reduced pressure to yield 62 parts (99% of the theoretical amount) of crude 2-methyl-4-chloro-5-nitrobenzene-1- methyl su fone. This product melts at 127-130". The pure product (M.P. 137) is obtained in a yield of about by recrystallization from ethanol, 10 parts of ethanol for every part of crude Z-methyl-4-chloro-5-nitrobenzene-lmethyl sulfone being required.

50 parts of 2-methyl-4-chloro-5-nitrobenzene-1-methyl sulfone are dispersed in a mixture of 60 parts of ethanol and 140 parts of water. To the well stirred mixture there is added at 80 to 82 within about 30 minutes a freshly prepared solution of 25.2 parts of sodium sulfite in parts of water. During the addition of the sulfite solution, the pH is maintained in the range of 7.5 to 9 by addition of a few drops of diluted hydrochloric acid. To complete the reaction, the mixture is stirred at the same temperature for an additional 10 minutes. Thereafter, 32 parts of solid sodium chloride are added and the reaction mixture is cooled down to 10. A thick slurry is formed which is filtered off by suction and the obtained crude product is purified in the following manner: The wet filter cake is dissolved in 250 parts of hot water, cooled down to 25 to 35, clarified by filtration, the filtrate is then salted out (n) diethylamino-sulfonyl at 60 to 70" with 55 parts of soiid sodium chloride and pyrrolidino-sulfonyl cooled to 10. Thereby, the sodium salt of the 2-nitro-4- (p) piperidino-sulfonyl methylsulfonyl-S -methy1benzene-1-sulfonic acid is ob- (q) morpholino-sulfonyl tained in nearly colorless crystals. The product is filtered 5 (r) 2,6-dimethylmorpholino-sulfonyl otf and dried at 80 under reduced pressure. This inter- (s) hexamethylene-imino-sulfonyl mediate l5 oblamedmaylfild of and fol'owing otherwise the procedure given in the ex- 52.5 parts of the sodium salt of 2-n1tro-4 -methy.su l- 1 The intermediate products (b) to 1 inclusive fortyl-S-rnethylbenzene-l-sultonic acid are dissolved loll produced in the Same manner as described in Example 1 900 l of After ralnng the temperature to 30 for intermediate (at) using the corresponding 2-methyl-4- a solution of 28 parts of sodium hydroxldem 65 part Of chlorophenyl-S-nitro-l-alkylsulfones as starting materials. water poured 1n, then a solution of sodium hyp c The intermediates (m) to (s) inclusive are produced as me and Sodlum hydroxlde, P P I 100 P f by described in Example 61 infra, for the case of 4,4'-divolume of a sodium hypochlorite SOIUUOH. containing 17 aminoyg dimethylaminosulfonyl m a y 1 parts of active chlorine and 4 parts of sodium hydroxide, 15 fonic acid is added dropwise within to minutes. A slightly exo- EXAMPLE 2 SIO2CHJ SHzCH; onto-f -CONH@CH=CH XNHCO-OCHI 69g, 503% S OaNB (BCH;

thermic reaction takes place and the temperature remains 52-6 par f 4.4'-diamin0-6.6'-dimethylsulphonyl-stilwithout external heating at 30 to The di-sodium salt l acid in 2000 Parts y Volume of of 4,4'-dinitro-6,6-dimethylsulfonyl stilbe.ie-3,3-disuly o toluene are heated to at this termfonic acid separates in glittering, yellow needles from the 25 Peralufe While Stirring. first 100 Parts y Volume of dark brown solution. After the addition of the above hydrous Pyridine and then! Within 15 minules- Solution sodium hypochlorite solution. the reaction mixture is of 60 Paris of 2,44imeth0xybenl0yl Chloride in 300 stirred for 1 hour at 35. The separation of the new stii- Parts of anhydrous toluene are added- The yellowish $115- bene derivative is completed by the addition of 25 parts Pension obtained is Stirred for 1 hour at Al the sodium chloride, the whole is cooled down to 15 to 30 end of this time, another portion of 25 parts of 2,4-dimeth- 20, the product filtered off, washed with aqueous 5%- Oxybenzoyl chloride in Parts y VQlume of anhydrous sodium chloride solution and dried at under vacuum. toluene is added and the whole is Stirred for 2 hours at The yield is 32.5 parts of di-sodium salt, corresponding to 100 110- After cooliflgv the Y Q Wecipilaie i8 3301 pans of the free acid (62% of the theoretical filtered ofi, the product is suspended in 2000 parts by vol- 35 ume of water and, at 5060 while stirring, 15% sodium carbonate solution is added until the pH of the mixture of water, 2 parts of acetic acid are added and the whole remams at Any toluene and PYridifle rFmaining is is heated for 30 minutes at 80 to while stirring well. removed Wlth Steam, e aqueous suspension 15 cooled to 19.2 parts of the di-sodium salt of 4,4'-dinitro-6,6'-dimethand therale Yellowlsh rejacnon product of above ylsulfonyl-stil'bene-3,3'-disulfonic acid are added to the 40 fofmula whlch separates out filtered After washing iron suspension at 90 to within a time of 20 minutes. with Sodlum chlonde 801mm the P P is dried The reaction mixture is then stirred for 1 hour at the boil. at vacuo' A Pa1e yellows}? Powder 15 obtained Thereafter an aqueous solution of 2.4 parts of Sodium the dlluted aqueous solution of which has a blue fluorescarbonate is added and then the iron residue is filtered off cence,in daylight hot and is washed with hot water until the filtrate gives no product can be used for the bnghenmg of cellulose more diazo reaction. The yellowish solution is acidified fibers (39mm fabnc can be chefmcany and Ppticany with 15 parts by volume of 30%-hydrochloric acid, whereone Step b the P of brighten by 4,4'-diamino-6,6-dimethylsulfonyl-stilbene-3,3-disuli a i foni: acid Separates as a Slightly cream colored precipi mg liquor with and without bleachers giving off chlorine tate. This intermediate product is filtered off, washed with 50 the product glves beautiful neutral white effectsamount).

20 parts of cast iron powder are suspended in 500 parts water and dried at 80 under reduced pressure. EXAMPLE 3 (|)CH; sloicm slozcn C|)CH3 CH CONH -cn=cn -xnc 00-011,

CH3 SOQNB 803KB CH1 Products having a similar effect are obtained by replac- 14.5 parts of dry disodium salt of 4,4-diamino-6,6-diing the 40 parts of 4,4-diamino-6,6-dimethylsulfonyl-stilmethylsulfonyl-stilbene-3,3'-disulfonic acid are suspended bene-3,3'-disulfonic acid by an equimolar amount of one 60 in 125 parts by volume of abs. pyridine, 10 parts of 2- of the 4,4-diamino-stilbene-3,3-disulfonic acids [intermethoxy-4,5-dimethylbenzoyl chloride are added to the mediates (a) to (5)] which bear in 6- and 6'-position the mixture and the whole is heated for 2 hours at while following substituents: stirirng. At the end of this time another 10 parts of 2- b) l lf l methony-QS-dimethylbenzoyl chloride are added and the (c) B-methoxy-ethyl-sulfonyl 65 whole 1s stirred for another 2 hours at 110. To work up (d) p. th xy th l lf l the product, 50 parts by volume of water are added to the (e) i th l lf l reaction mlxture at 80 to 90, the reaction is made alkaline (f) fi th lf l with 30% sodlum hydroxide solution while stirring until (g) .benzyl lf l phenolphthaletn paper is clearly red, the pyridine is re- 0 fi h l th l lf l 70 moved with steam and, after cooling, the yellowish reac- (i) 3 4 di hl b l lf l tron product of the above formula is filtered off and (j) 4-bromo.b yl lf l washed with 3% sodium chloride solution. After drying, (k) 2,4.di h pb p lf l a yellowish powder is obtained which has a bluish fluores- (l) 4-methoxy-benzyl-sulfonyl cence in hot water. Like the products of the previous ex- (m) dimethylamino-sulfonyl 75 amples, it can be used for the brightening of cellulose substrata. This compound too is distinguished by very good stability to aqueous alkali hypochlorite solution.

By replacing the parts of 2-methoxy-4,5-dimethylbenzoyl chloride in Example 3 by equimolar amounts of the acid chlorides given in the second volume of the fol lowing Table I and using 14.5 parts of the 4,4-diaminostilbene 3,3'-disulfonic acid employed in said example or replacing the same by an equimolar amount of one of the intermediates (b) to (s) inclusive obtained as described after Example 1, while otherwise following the procedure given in the said example, corresponding end products 10 are obtained which are almost colorless to slightly yellowish powders of similar brightening properties as the products of Examples 1 to 3.

TABLE 1 Acid chloride Example No.:

4 (8-5) CHaO@-COC1 I OCH:

tlmrhcmofi 5 (11-5) OQ-COCI l CH -O 6 (8-5) cmoQcocn r (oi-S) canoQcorn l ocr s TABLE I.-C0ntinuetl Acid chloride SOzCH: SOgCH; OCllzCHzOll 5.26 parts of 4,4 diamino'6,6'-dimethylsulphonylstilben-3,3'-disulphonic acid are suspended in parts by volume of anhydrous pyridine and, after the addition of 6.5 parts of 2-acetyloxy-4-methylbenzoyl chloride, the whole is heated for 1 hour at 100-110. First 300 parts by volume of water and then, at 85-90", 15% sodium carbonate solution are added to the brownish reaction mixture obtained, the latter addition being made dropwise, until the pH of the mixture has risen to 99.5 and, on discontinuation of the addition of alkali, does not sink below 9. The pyridine is then removed with steam and the intermediate product of the formula $020K: BOzCH;

s (a-s) cmQ-cocr Eth e1 chlo'. olormate. Methyl thlorotormate.

S aNB S OaNa which is formed is precipitated as a yellow precipitate by the addition of sodium chloride. 8.39 parts of this intermediate product are dissolved in 200 parts by volume of water and 0.8 parts of sodium hydroxide and 1.6 parts of ethylene chlorohydrin are added dropwise while stirring at 60-70. When the reaction mixture no longer has an alkaline reaction, concentrated aqueous sodium hydroxide solution is added until the pH has risen to at least 12. Then ethylene chlorohydrin is added dropwise until the mixture has become neutral. The alternate addition of sodium hydroxide and ethylene chlorohydrin is repeated until a sample of the reaction mixture no longer shows a brown-violet colour with ferric chloride solution. After cooling, the pale yellow reaction product of the above formula is filtered off, washed with 4%- sodium chloride solution and dried at A yellowish, water soluble powder is obtained which also has good substantivity in spite of its good water solubility and it can be used as brightener for cellulose fibers.

Products having a similar action are obtained by using 6.5 parts of 2-acetyloxy-4-methylbenzoyl chloride or an equivalent amount of the acid chloride given in the second column of the following Table II, and also using 5.26 parts of 4,4 diamino-6,6' dimethylsulfonyl-stilbene-3,3-disulfonic acid employed in said Example 51 or replacing the latter acid by an equimolar amount of or of the intermediates (b) to (s) inclusive given after Example 1, and as stated in the third column of Table II by directly saponifying the resulting product, in the man- 13 14 ner described in Example 51, or by replacing in the Exwith sodium sulfite in a mixture of ethanol and water, ample 51, the ethylene chlorohydrin by an equimolar in the manner as described in Example 1 for the producamount of the bromides listed in the third column of the tion of the disodium salt of the corresponding methyl following Table II. sulfonyl compound. This product forms only faintly TABLE I1 5 coloured, water soluble crystals. 35 parts of sodium hydroxide and 0.1 part of sodium Acld Cmmde Bmmde laurate are dissolved in 100 parts of water, after the ad- Example No.1 dition of a solution of 0.1 part of manganese sulfate in 52 (HLM' f g gfgfifi sammficamm' 20 parts of water, there are added at a temperature of 53 (as).... 2- o yylc r 33" 24 parts of the above described sodium salt in 500 54 (Hymn g fifii D0, 10 parts of water within 10 hours while blowing into the rechloride action mixture a strong stream of oxygen. The brown 55 (HL'M ";$fi;; 3hydmxy'pmpy1bmmde' solution is then clarified and the well water soluble 4,4- 56 as)..... 4-ooeto -p y r Ethylene bromohydrin. dinitro 6,6 bis-dimethyl-sulfamido-stilbene-disulfonic 57 g fg g ch, sapomficmon, acid in form of its brownish disodium salt salted out by 58 (a-s) 3- ee t o ir y benzvlchloro- 4hydroxy-butyl bromide saturation with Sodium 9 rm 0. The reduction of this dinitro-compound into the re- 59 4acemlFy-benmyl Ethylene bmmohidrin quired diamino-product is carried out in the same manner chloride. 60 (8-5)..." 2,4bis(8eetoxy)benzoyl Do. as described in Example 1 for the production of the corchlorideresponding dimethylsulfonyl compound Products of similar good properties are obtained by EXAMPLE 61 replacing Example 61, but replacing in the same the SO:N(CHJ)2 s02N cHm omoQ-coNH-oH=cH QNHc0ocm oclll s'om soul born When in Example 2 the 52.6 parts of 4,4'-diamino-6, acylating agent (used in Example 51) by one of the acyl- 6' di methylsulfonyl stilbene 3,3 disulfonic acid ating agents used in Examples 1 to 50 inclusive, and/or are replaced by 58.8 parts of 4,4'-diamino-6,6'-bis-diby replacing in Example 61 the parts of dimethylmethyl-sulfarnido-stilbene-disulfonic acid, the d-sodium amine by an equimolar amount of one of the amines salt of the above mentioned acid is obtained which has, listed in Table III below, whereby intermediates (n) to in spite of its good solubility in water, similar brighten- 35 (s) inclusive listed following Example 1 and others are ing properties as the corresponding di-methylsulfonyl obtained. compound. This product is isolated from its aqueous solu- TABLE 111 tion by salting out with 15% of solid sodium chloride (calculated on the total weight of the solution). The purified product forms a slightly yellowish powder, the aqueous solution of which exhibits in daylight a pronounced bluish fiuorescense.

The 4,4-diamino 6,6 his dimethylsulfamido-stilbene-3,3'-disulfonic acid in the above example is obtained in the following manner:

94.5 parts of the sodium salt of 2-methyl-4-chloro- 5-nitro-benzene-l-sulfonic acid are added while stirring (a) diethylamine (b) pyrrolidine (c) piperidine (d) morpholine (e) 2,6-dimethyl morpholine (f) hexamethylene imine (g) N-methyl-N-ethyl amine (h) di-(fi-rnethoxy-ethyDamine (i) di-propyl amine well to 480 parts of chlorosulfonic acid at 15 to 20. EXAMPLE 62 SOzCH; 501cm cH=coNH -CONH CH=CH@NHCO NHCOCH s0,H soul The whole mixture is subsequently stirred at 75" for a (i) 33,5 parts f 4,4'.di i -5 6-di th 1 h 1 further two hours. In order to isolate the formed 2- stilbenggazdisulphonic acid are suspended i 500 parts methyl-4-chloro-S-nitrobenzene-l-sulfonic acid chloride, the solution is ured onto 1400 arts of crushed ice, the grayish prccipigze is filtered omgvashed well with wawr 60 henzoyl chloride are added to the suspenslon whlle stirand dried at 60 in vacuum. The sulfochloride melts at rmg mom temperature- The temperature spomane' ll4-1l6 and cristallizes from acetone in nearly white to and the reaction mixmre thickens dl into a stifif yellow paste. The mixture is then heated to A solution of 82 parts of this sulfochloride in 400 within 30 minutes and, after it can no longer be parts of acetone is poured, while stirring, onto 600 parts stirred, it is coled to 30. After the addition of 700 parts by volume of pyridine and 40 parts of pulverised 4-nitroof crushed ice. To this suspension of 2-methyl-4-chloroby volume of abs. toluene the mixture can again be stirred S-nitrobenzene-l-sulfonyl chloride is added a solution of and it is heated to 110-115 while stirring and then re- 35 Parts of dimethylamine in 50 Parts of Watef- During fluxed for 30 minutes at this temperature while stirring. the addition the temperature is p down to to The yellow slurry obtained is cooled to 30, filtered under The yellowish slurry is then filtered and z'methyl' suction and the residue is washed with benzene. The yelf 'f g gggg b ififi g g sgfiggl aggi washed low filter cake is then suspended in 2000 parts of water,

To obtain the sodium salt of 2 nitro 4 'dimethy1su]f sodium carbonate is added at 70-80 while stirring until amido-S-methylbenzene-l-sulfonic acid the 2-methyl-4- Phenolphthalein P p remains y befllene and chloro-S-nitrobenzene -1- sulfodimethylamide is reacted pyridine present being removed by bubbling steam through and, after cooling, the yellow reaction product of the formula 801C113 SOQCHI sulfamidostilbene-3,3'-disulfonic acid used in Example 61 and by using in lieu of acetic acid anhydride in step SOJNB SOaNa is filtered off and washed with 2.5% sodium chloride solution.

(ii) 200 parts of cast iron powder are suspended in 6000 parts of water, 40 parts by volume of acetic acid are added and the whole is heated for 30 minutes at 80-90 while stirring. The damp yellow filter cake of the dinitro compound mentioned above is added to the iron suspension at 90-95 and within 30 minutes and the reaction mixture is then stirred for 3 hours at the boil. After this time, 15% sodium carbonate solution is added until the pH of the mixture is 8-9 and then the iron residue is filtered off hot and is washed with hot water until the filtrate has, for practical purposes, no more diazo reaction. A yellow solution is obtained which contains the N,N-bis-(p-aminobenzoyl) compound of the sodium salt of 4,4-diamino 6,6 dimethylsulphonyl-stilbene-3,3-disulphonic acid.

(iii) Acetic acid anhydride is added dropwise to the amine solution obtained while stirring at 80-85" until a sample shows no diazo reaction. After neutralising with aqueous sodium hydroxide solution, the disodium salt of the N,N'-bis-(p-acetylaminobenzoyl) derivative formed is obtained as a whiteish precipitate which can be filtered after addition of the same volume of 25% sodium chloride solution. After cooling, it is filtered off under suction, washed with 2% sodium chloride solution and dried in vacuo at 70-80. A yellowish powder is obtained which dissolves in hot water and which can also be used for the optical brightening of cellulose fibres.

By using, instead of acetic acid anhydride, chloroacetic acid anhydride, p-bromopropionic acid anhydride or 4-methylphenoxyacetic acid anhydride and otherwise following the procedure given in Example 62, the corresponding bis(chloro-acetylamino), and bis-(fi-bromopropionylamino) or bis-(4-methyl-phenoxyacetylamino) compound, respectively, are obtained which have the same effect.

To produce the urethane derivative:

ammon a-Q ONHQ SO;Na

which is an equally effective brightener, chloroformic acid ethyl ester is added dropwise at 7580 while stirring to the solution of the sodium salt of 4,4'-bis-(p-aminobenzoylamino) 6,6 dimethylsulphonyl stilbene 3,3- disulphonic acid and the acid liberated is neutralised with sodium carbonate solution. When no more diazotizable amino groups can be traced, the reaction product is precipitated in a form which can be filtered by the addition of sodium chloride.

Both the diacetyl derivative as well as the urethane derivative are considerably more stable to sodium hypochlorite than the corresponding derivatives of 4,4'-bis-= (p-amino-benzoylamino) -stilbene-6,6'-disulphonic acid.

Products of similar good brightening properties, and especially of good fastness to chlorine are obtained by repeating Example 62, and using 4,4-diamino-6,6-dimethylsulfonyl stilbene-3,3'-disulfonic acid or one of the other starting acids listed following Example 1 under (b) to (s) inclusive, or 4,4-diamino-6,6'-bis-dimethyl- SOzCHa (iii) an equimolar amount of one of the aeylating agents listed in Examples 4 to 50, inclusive, or by an equimolar amount of one of the acetoxy-substituted acyl halides and chloroformates listed in examples 51 to with subsequent saponification or with subsequent reaction with ethylene chlorohydrin as in Example 51 or one of the bromides listed in Examples 55, 56, 58, 59 and 60.

The chlorine-fastness of the compounds produced according to Example 62 and the above described variations thereof, is particularly surprising, because one would have expected that the outer -NHCObridges would be particularly susceptible to the attack of chlorine, as it occurs in modern detergent mixture which contain at the same time chlorine-yielding bleaching agents.

EXAMPLE 63 Parts Dodecyl sulphate 8 Dodecylbenzene sulphonate 11 Sodium tripolyphosphate l1 Tetrasodium pyrophosphate 17 Sodium sulphate 37 Brightener according to Example 2 0.2

are worked into a paste with 170 parts of water. The paste is dried at 60 and then milled.

6 parts of this washing powder are dissolved at 7080 in 1000 parts of water and 0.5 part of a sodium hypochlorite solution, corresponding to 0.5 part of active chlorine, are added. After leaving for 30 minutes, uncolored cotton fabric is washed (liquor ratio 1:30) for 30 minutes at 80 in the washing liquor so obtained, then rinsed and dried. A beautifully brightened fabric is obtained.

EXAMPLE 64 Cotton cretonne fabric is washed for 20 minutes at 60 (liquor ratio 1:30) in a washing liquor which contains, per liter, 5 g. of a washing agent of the composition:

After rinsing and drying, a fabric having a neutral white appearance is obtained.

EXAMPLE 65 A mixture of 4.7 parts of sodium chloride, 0.3 part of lithium hypochlorite and 0.011 part of the brightening agent mentioned in Example 2 are dissolved at 60 in 1000 parts of water. If uncolored cotton cretonne fabric is treated for 20 minutes at 60 with this solution, liquor ratio 1:30, then after rinsing and drying, cotton fabric 01 a high degree of whiteness is obtained.

503% SOsNa -N H-acyl in the described manner in the presence of 0.3 part of lithium hypochlorite, the measured fluorescence effect shows a 30% drop.

EXAMPLE 66 10 parts of white cotton household linen are washed for 30 minutes at 40 in 200 parts of a washing liquor which contains 5 g. per liter of nonylphenol polyglycol ether (with 12 ether oxygen atoms) and 0.005 g. of the brightener obtained according to Example 1, and then rinsed and dried. The cotton goods so washed have a considerably more white appearance than a comparative sample washed in the same liquor without brightener.

If, in this example, the washing process described is repeated 15 times then a considerable increase in the white effect can be observed without incurring an undesirable discoloration of the goods.

A brightening effect which is equally good for practical purposes is attained if the washing is performed in a washing liquor which contains 6 g. per liter of a nonionogenic washing agent of the composition:

Percent Nonylphenol pentadecyl glycol ether 11 Sodium tripolyphosphate 33 Sodium pyrophosphate 11 Sodium silicate 10 Sodium sulphate 20 Sodium carbonate 2 Carboxymethyl cellulose 2 Water -s 11 0.005 g. of the brightener obtained according to Example 3, and an amount of sodium hypochlorite corresponding to 0.3 part of active chlorine. In this case too, an increase in the degree of whiteness is obtained on repeated washing without any undesirable discolouration of the goods.

I claim:

OCgHs 18 1. An optical brightener which in its free acid form is of the formula SOgX CO-R:

l SUJI wherein each of R and R represents a member selected from the group consisting of (lower alkyl)-, (lower alkoxy)-, R -(lower alky1)-, R -(alkoxy)-wherein the alkoxy moiety has from 2 to 4 carbon atoms,

and.

in which radicals R and R the substituent R represents a member selected from a group consisting of hydroxy, lower alkoxy, hydroxy-loweralkoxy, phenoxy, chlorophenoxy, bromophenoxy, lower alkyl phenoxy and lower alkoxy-phenoxy,

R represents a member selected from the group consisting of hydrogen, fluorine, chlorine, bromine, lower alkyl, lower alkoxy, hydroxy-lower alkoxy and lower alkoxy-lower alkoxy,

R represents hydrogen, fluorine, chlorine, bromine, lower alkyl, lower alkoxy, hydroxy-lower alkoxy or lower alkoxy-lower alkoxy.

p represents one of the integers 1 and 2, and

q represents an integer ranging from 1 to 3,

and in which formula SOzCH; 001B;

l :11 SOiH 3. An optical brightener which in the free acid form is of the formula:

4, An optical brightener which in the free acid form is of the formula:

5. An optical brightener which in the free acid form is of the formula:

6. An optical brightener which in the free acid form is of the formula:

0 C3137 S'OzCIh soicnt 30311, orb-G4: ONH CH=CHQNHC OQCH;

SOsH 803K 7. An optical brightener which in the free acid form is of the formula:

can, SOzN(CHa)1 som cum 0cm CHzO-G-CONH( CH=CH-NHCOQOCH;

s03 sour 8. An optical brightener which in the free acid form is of the formula:

References Cited UNITED STATES PATENTS 2,690,435 9/1954 Savidge et a1. 260-507 3,260,715 7/1966 Saunders 260-240 DANIEL D. HORWITZ, Primary Examiner, 

